Geomagnetic fluctuations with the frequencies of torsional oscillations of the Earth

Winch, D. E.; Bolt, Bruce A.; Slaucitajs, L.

doi:10.1029/jz068i009p02685

Cited by 15 publications

(4 citation statements)

References 7 publications

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“…Turbin et al [1972], with data from seven high-latitude stations for eight selected disturbances, reported that peaks in the region from 10 to 60 min correspond to natural torsional vibrations of the earth. Winch et al [1963] reported finding the earth torsional oscillation periods (43.1, 29.0, and 22.4 min) in the frequency analysis of Port Moresby magnetograms following a Chilean earthquake. The spectra presented in the present paper show no such dominant periods for the averaged data.…”

Section: Spectral Amplitudes Maximize At the Auroral Zonementioning

confidence: 99%

An analysis of the spectra of geomagnetic variations having periods from 5 min to 4 hours

Campbell¹

1976

J. Geophys. Res.

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The geomagnetic field variation spectra for the period range of 5 min to 4 hours were analyzed at 64 world observatories to discover systematic behavior in the spectral composition that could be associated with the time of day, season, solar cycle, activity level, component direction, and geographical location of the station. There was found no consistent frequency location for peaks in the spectral composition. Rather, the displays of spectral amplitudes A were mostly ‘linear’ in form, often obeying A ∼ Tm, where T is the period. The spectral slope m was usually close to 1.0 but varied at times from 0.5 to 2.0. The amplitudes always showed a maximum at the auroral zone latitudes, a minimum near 20°−40°, and a minor maximum near the equator. The positions shifted equatorward with increasing activity. The relative growth in amplitude with rising activity varied with latitude. Seasonal peaks in activity were found at equinoctial months. A summertime minimum occurred at auroral zone stations; elsewhere a summertime enhancement occurred. General findings emphasizing the North American hemisphere and the year 1965 are presented in a number of tables and graphs.

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Section: Spectral Amplitudes Maximize At the Auroral Zonementioning

confidence: 99%

An analysis of the spectra of geomagnetic variations having periods from 5 min to 4 hours

Campbell¹

1976

J. Geophys. Res.

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“…Частота F моды 0 S 2 определялась на основе спектрального анализа геомагнитных вариаций [Winch et al, 1963], зарегистрированных в периоды сильных землетрясений с магнитудой в интервале 7-9 из каталога USGS. Анализировались данные, полученные в течение первых 5-10 суток после сейсмических событий, произошедших с 2015 г. по сентябрь 2022 г.…”

Section: исходные данныеunclassified

The Effect of the Earthʼs Rotation Speed to the Frequency of the Fundamental Mode 0s2

Спивак,

Локтев,

Тихонова

et al. 2024

Динамические Процессы В Геосферах

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Анализируется частота фундаментальной моды F собственных колебаний Земли 0S2, выделенная в спектрах геомагнитных вариаций в Геофизической обсерватории (ГФО) «Михнево» ИДГ РАН, в период сильных землетрясений. Показано, что величина F принимает разные значения в зависимости от даты события, причем значения F выше в периоды, характеризующиеся уменьшением скорости вращения Земли, и ниже - в периоды ее увеличения. По результатам сопоставительного анализа результатов магнитных измерений и данных каталога открытого доступа IERS получена эмпирическая зависимость между вариациями F и скоростью вращения Земли. The frequency of the fundamental mode F of the Earth’s natural oscillations 0S2, identified in the spectra of geomagnetic variations at the Mikhnevo observatory of the IDG RAS, during strong earthquakes is analyzed. It is shown that the value of F takes different values depending on the date of the event, and the values of F are higher during periods characterized by a decrease in the Earth’s rotation rate, and lower during periods of its increase. Based on the results of a comparative analysis of the results of magnetic measurements and the data of the IERS open access catalog, an empirical relationship was obtained between the variations in F and the Earth’s rotation rate.

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“…Весьма интересным в плане межгеосфер ных взаимодействий представляется рассмотре ние проявлений собственных колебаний Земли (СКЗ) в вариациях магнитного поля. Действи тельно, изучение тонов и обертонов СКЗ, а так же расщеплений мультиплетов позволяет по лучать информацию о геометрии и свойствах отдельных внутренних областей Земли, вариа ций скорости вращения и изменения ее формы [Адушкин и др., 2017в; Жарков, 2012; Милюков, 2005;Милюков и др., 2015;Dahlen et al, 1968;Gilbert, Backus, 1968;Winch et al, 1963;Suda et al, 1998]. Хотя и в меньшей степени по срав нению с приливной деформацией, СКЗ связа ны с изменением формы Земли в целом, ее внутренних геосфер, включая жидкое и твердое, Сильные возмущения атмосферы проявля ются не только в виде изменений температуры и влажности воздуха, атмосферного давления и скорости ветра, но вызывают также замет ные вариации геофизических полей, в частнос ти, электрического поля, микросейсмического фона и акустических колебаний у земной по верхности.…”

Section: проявление собственных колебаний земли в геомагнитных вариацияхunclassified

Problems of interaction of geospheres and physical fields in near-surface geophysics

Адушкин

Спивак

2019

Физика Земли

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The main directions and problems addressed by near-surface geophysics – the new currently actively developing scientific discipline – are formulated and discussed. A combined approach is proposed for exploring the geospheres’ interactions at the Earth’s crust – atmosphere boundary where mass- and energy exchange between the internal and external geospheres is most intense and for studying the interactions and transformations of the geophysical fields in the surface zone of the Earth including its biosphere. New results obtained in the studies of inter-geosphere interactions and physical fields of the Earth are presented. It is emphasized that establishing the geophysical conditions of human environment and characteristics of manmade activity is of great importance.

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Geomagnetic fluctuations with the frequencies of torsional oscillations of the Earth

Cited by 15 publications

References 7 publications

An analysis of the spectra of geomagnetic variations having periods from 5 min to 4 hours

An analysis of the spectra of geomagnetic variations having periods from 5 min to 4 hours

The Effect of the Earthʼs Rotation Speed to the Frequency of the Fundamental Mode 0s2

Problems of interaction of geospheres and physical fields in near-surface geophysics

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